Help needed! Where is “Lasell, North America”?

I recently discovered – and in the process, knocked down a long-standing brick wall in my research – a newspaper article that contained a death notice for my 3x great-grandfather Thomas Collingwood. He was a bit of a mystery before, but I have confirmed that he died in the USA in 1853, aged just 31. He left Liverpool in 1850 with his wife and young son, arriving in New Orleans, and could then be found in the 1850 US census living in St Charles, Missouri. Some time before his death, his pregnant wife and his son headed back to England where their daughter Agnes – my great-great-grandmother – was born in 1852.

The death notice, printed in the Carlisle Patriot, the Newcastle Courant and a number of other papers on Saturday 12th November 1853, read:

“At Lasell, North America, on the 25th August, aged 31, Thomas, son of the late Capt. W. D. Collingwood, of Sunderland”

As I had never heard of a place called Lasell in the USA, I did a little research into where it was. The majority of the results I found all referred to a Lasell College based in Auburndale, Newton, Massachusetts. It was founded in 1851 as the Auburndale Female Seminary by Edward Lasell, who was inspired to invest more in women’s education. My guess was that perhaps Thomas was teaching at the college in the 1850s, so I got in contact with their library to find out more. My email was forwarded to their archivist who very nicely did a search in their records for any mention of Thomas.

Sadly, nothing came up from the search but she did find reference to an island in Maine called Lasell Island. A bit of searching revealed this to be a small island in the West Penebscot Bay and now contains only a holiday home. I think it is unlikely that Thomas was here. Perhaps he did briefly work at Lasell College, yet no records of him there exist.

Would readers of the newspapers have known where “Lasell, North America” was? How well-known was the college at this point? Would “Newton, Massachusetts” or “Boston, Massachusetts” been more widely recognised?

Can you help me find where ‘Lasell, North America’ is? Or perhaps any other reference to Dr Thomas Collingwood in the USA in the 1850s?